This invention relates to methods and apparatus for sorting timber pieces and, more particularly, to methods and apparatus for sorting timber pieces while the same are transversely transported on a conveyor on which the timber pieces are supported by consecutively arranged pairs of supporting members arranged in side-by-side fashion and from which the timber pieces are dropped in accordance with a preset program at depositing sites according to desired characteristics.
Timber sorting apparatus which have proven to be highly advantageous relative to most conventional sorting apparatus are disclosed in applicant's Finnish Pat. No. 44 783. The method and apparatus disclosed in this patent are advantageous in that the timber pieces are transported in a manner such that the supporting structure is subjected to only a minor torque and are therefore well adapted to handle even heavy timber pieces. The timber supporting pieces can be spaced more closely to each other than in conventional apparatus even where timber pieces having a great breadth are being handled so that high outputs are obtained even when the conveyer is run at a relatively low speed.
However, there are certain disadvantages inherent in the construction and operation of the timber sorting apparatus as disclosed in Finnish Pat. No. 44 783. More particularly, in the apparatus disclosed in the Finnish patent, the timber piece is held by a hook-like member which is connected to a fixed arm member. However, this construction has the drawback that in order to accommodate variations in the length of the timber pieces, it is necessary in practice to normally use four or five groups of such members and, consequently, four or five triggering devices are required in order to actuate the hook-like member during the sorting procedure. If only a single triggering device is to be sufficient, it is necessary to interconnect all of the hook-like members with a single connecting shaft which itself is actuated by a single triggering device. In this situation, however, two separate shafts at each dropping station are required, namely one which is fixed and one which is rotatable. Of course, this necessity renders the apparatus relatively expensive and, additionally increased the distance between adjacent timber pieces.